A mail client is an application program that provides a user the ability to send and receive emails on the Internet. Several methods exist for authenticating an email communication between mail clients.
FIG. 1A illustrates a block diagram of a trust model based on certificates of authority. FIG. 1B illustrates a block diagram of a trust model based on public and private key pair. A certificate of authority provider 102 certifies different users: Steve 102, and Bob 106. As such each user 104, 106 certified by the provider 102 has a certificate 108, 110 issued by the provider 102. The identity and public key are all signed by the certificate of authority 102. In a large SMIME deployment, all users will be made to trust the certificate authority, and so by implication, all user certificates that have been issued by the certificate authority. Upon receipt of a signed email, the email will show as being signed. However, this process is onerous for smaller deployments who cannot afford to set up a certificate authority. Also, if the certificate is used only to communicate with a small number of peers, it may not be economically viable to buy a certificate from a third party. Although a user can create his own self-signed certificate, this process is cumbersome. Additionally, the certificate must be transmitted to a peer if it is to be useful for encryption purposes, and the mechanism for this is also cumbersome.
As such, a need exists for a method or system that helps overcome one or more of the above-described limitations.